User blog comment:Metaron Isard/Can Dante Drown/@comment-5114165-20120525025902/@comment-775152-20120525033447

Well, the Abyss beneath the Broken Bridge wasn't really underwater in the same sense that's being talked about here. It was "under water" but Dante wasn't in the water. In the later missions with the Ghost Ship, Dante is swimming underwater and there's no penalty no matter how much time you spend down there.